Parah 6:2-3

Parah 6:2

Rabbi Meir and Rabbi Shimon say that if the ashes floated on top of the water, one may take them and use them to sanctify other water; the Sages say that any ashes that have touched water may not be used to sanctify any other water. Rabbi Meir and Rabbi Shimon say that if one emptied out the water and some ashes were found at the bottom, they may be dried and used to sanctify other water; the Sages say that any ashes that have touched water may not be used to sanctify any other water.

Parah 6:3

If one mixed the sanctification water in a trough that had a jug in it, even if its neck was narrow (so that no ashes entered it), the water in the jug is sanctified (because it mingled with the water in the trough). If there was a sponge in the trough, the water in the sponge is invalidated (because a sponge isn’t a vessel). In such a case, one should empty out the water until he gets to the sponge. If he touches the sponge, even though water is washing over it in whatever volume, the water is rendered unfit (because unfit water from the sponge is squeezed into the water).